6/17/2021

1. What is happening, weather-wise?

2. What does that mean for your lawn?

3. What does it mean for your ProLawns Program?

4. What can you be doing?

1) What is happening, weather-wise?

Unprecedented Harsh Conditions

Drought Information Link

“Near record heat along with dry conditions for the first week of June has led to a rapid deterioration in drought conditions across central and southern Minnesota and western Wisconsin. Though the entire region is seeing short term precipitation deficits, longer term deficits are greatest in areas that are depicted with moderate drought (D1) or worse drought. Much of the area within D1 or worse drought conditions has seen about half their normal precipitation over the last 6 months. Over the next 2 weeks, above normal temperatures and dry conditions are expected to continue. This will continue to foster further expansion of drought conditions across Minnesota and Wisconsin going through the rest of June.”

Lawns are experience heat stress and drought stress (turning purple) and many are going dormant (turning yellow/brown). Going dormant is a good thing! This is a defense mechanism to preserve itself. The lawn has shut itself down until more regular temperatures return and it gets appropriate amounts of water.

Question: Why are some patches green and some yellow? Answer: Different varieties of grass. Your lawn is made up of many different types of grass that have different tolerances to heat and drought.

Another condition that is seen is Ascochyta Leaf Blight… even on irrigated lawns. The disease appears to be enhanced by soil moisture fluctuations, especially drought stress caused by watering restrictions and poor irrigation system coverage. We see it especially on lawns that have been sodded in the last few years that usually have poor subsoil from the home’s construction. Ascochyta blight is primarily a leaf and not a root or crown disease so it rarely causes plant mortality. Turfgrass usually recovers completely after a couple of weeks. Management practices are seen here.

The one bit of good news is that, for the most part, turf under trees has remained healthy. This means that there is somehow enough moisture in the soil to for the turf. “Trees drink first” is one rule of nature; in severely dry conditions, the turf in the root zone under tress starts to go dormant first as the tree sucks the moisture from the soil. We haven’t seen this. We believe this means that with milder temperatures and just a bit of rain, lawns will spring right back to health!

We apply fertilizer in granular form (fully changed over in 2021). It requires rain/irrigation to activate, otherwise it waits for the correct conditions. Our fertilizer does not burn grass and our applications now will help your lawn recover.

To put in perspective: If you managed to survive a week in the Sahara without food or water, were rescued and provided water, don’t you think you’d also appreciate some food too? After a week without?? Your lawn is the same way. Our fertilizer applied now is the patiently waiting buffet for when your lawn gets the water it needs. Making your lawn wait for weeks after it gets the water it needs before it gets the nutrients it needs to recover will significantly delay it getting back to a beautiful appearance.

In general, we’re never fertilizing for today, tomorrow or even this week. We’re supplying what your lawn needs for the future when it’s ready for it. We’re fertilizing for 1 to 8 weeks from now – there will be rain in this time period even though it’s dry now.

As important as fertilizer, we’re also getting rid of the weeds that are taking advantage of the weakened state of your turf. They’re trying to cloud out your grass while it’s struggling. Weeds thrive in these conditions and if you let them, will use up the nutrients that you turf will need to recover. Without our attention, broadleaf weeds and crabgrass will dominate your turf; choosing to skip applications will likely mean we won’t be able to control weeds to our standards for the remainder of the summer.

• DO NOT water mid-day. Watering between 9am and 5pm does not “cool down” the turf, it traumatizes it. Even irrigated grass partially shuts down during the heat of the day. Imagine your heart rate and physical state if you were exhausted, went down for a nap and then were sprayed with very cold water. It’s even worse for grass with the biological processes going on for it’s self preservation.

• DO NOT water dormant grass unless you will be able continue watering it regularly and well. Grass that’s gone yellow has shut itself down as a defense mechanism from the heat and drought. It is still very much alive in it’s root system and will come back with appropriate rain and milder temperatures. If it’s dormant (sleeping) and it get’s woken up with irrigation but then has to cycle right back into dormancy, it really messes with the natural defense processes of the grass. Only bring your turf out of dormancy if you can maintain appropriate watering practices.

• DO NOT assume that you irrigation system settings that keep your lawn green in normal conditions are appropriate for the conditions we’re experiencing now. They would be appropriate if temperatures had been 14* cooler on average and if we’d received 3″+ of rain over the last three weeks. We have not had either of these conditions and that needs to be compensated for to maintain the same turf conditions.

• DO NOT mow at your regular height (unless you regularly mow at the highest possible setting). Mow as high as your mower possibly can. We recommend doing this all summer regardless of weather conditions but it is mandatory now. The taller the grass, the deeper the roots. The roots need to go deep to tap whatever reserves of water are available in your soil. Taller grass also shades the soil better to reduce evaporation.

What should you do

• Water appropriately unless you’ve chosen to let your grass go dormant. Here’s how:

  • More than a half inch at a time will saturate the soil, start to run off and be wasted.

  • In normal temperatures and without any rain it takes about one inch of irrigation per week to support healthy grass. It takes more than that in these conditions to achieve healthy turf.

  • For an average irrigation system spray sprinkler zone, it takes 60 minutes to achieve 0.5 inches of water. This means it takes 120 minutes per week per zone to get the required irrigation for a healthy lawn, in normal temperatures, in the absence of rain

    • Most irrigation systems are set to 15 minutes per zone, running three days per week. That equates to 45 minutes of run time or about 1/3 of what would be required for healthy turf in the conditions we’re experiencing.

    • If you run 20 minutes per zone, your system should be running every single day.

    • “Hot areas”; South facing hills, poor subsoil, full sunlight should receive a double hit of irrigation. Called “cycle and soak”, run these zones first then the rest of the lawn, then those zones again at the end of the regular cycle. This reduces run-off.

  • Instructions for watering with a hose sprinkler will vary too much to give specific instructions here. To determine run time, place a cup or two under the sprinkler and measure how much time it takes to fill the cup(s) with 1/2″ of water. Run your hose sprinkler this amount of time, 2-3 times per week, to maintain healthy turf.

• Again, if choosing to let the lawn go dormant, do nothing. Remain patient until we get some rain and milder temperatures.